Questions For The Polymer Clay Artists

[ghostrider]

I'm not sure if this is the correct forum, so please forgive me and move to appropriate one if necessary.

I'm interested in input from those who have knowledge and experience about/with this.

I've been experimenting a lot lately with different brands, and one thing I like about Premo! is the variety of colors and effects it comes in. (I know I can mix my own with other brands, I just haven't gotten there yet). The problem I have is that it seems that no matter how long I bake it, how hot or warm I bake it, or how many times I bake it, it is still soft and rubbery. I understand that it's supposed to basically be like PVC, and that Premo! was formulated to be flexible, but is it supposed to be like this?

I made an awesome blank for a friend recently, and he reported that, "once he got past the outer layer, it became soft and eventually blew apart." I've got a ¾"x3/4" blank that I made (while experimenting for the SegBox) that I've baked probably five or six times minimum (I got to the point where I threw it in with every other batch of Premo! I made, and lost count). Finally, today, just to see how far things could go, I baked it at 275* for probably two hours. I also decided to not burry it in baking soda this time. Needles to say, the top side was well burnt, while the bottom part was fine. Also, on a recommendation from someone in a Yahoo! group, I used the ice water method. Even still, once it had completely cooled, it was still somewhat soft enough for me to push in and it still flexed. I broke it in two to see the inside, and it was still soft enough for me to indent with my finger nail (It did however, spring back out gradually), and I could feel it give under thumb pressure. It was easily manipulated (not hard like balsa or basswood), and I got very similar results with a Sculpey III blank (my first exposure to PC) that I actually did turn. It too was spongy enough to push in. It seems to have a memory kind of like those firm/soft insoles that Spenco used to make, but quite a bit firmer.

I've used Cernit, Kato, and Fimo, and neither of those seems to present this problem. I've peeled cured Kato off of brass tubes to find that it's so hard that without the tube it is extremely stiff and strong. I've turned Fimo, and Cernit both, also with good results (and of course some learning examples along the way).

I've managed to have at least one good set with the Premo! (a faux Paua Shell) that I was careful with (baked it about three, maybe four times), but I still wonder how well Premo! will hold up over time with this type of consistency, as well as how this sort of flexibility with affect the finish. A couple times I've just decided to give up on Premo!, but then I'll have a success like the last Cigar I made, and keep trying.

Does anyone else have experience with this brand? What are your views, and thoughts from those experiences? Is there something I can do differently to get better results?

Any insight and help will be appreciated.

David

 

[KnB Polymers]

I use Premo more than anything ... that and Kato.
If I am reading this right, you are trying to bake a thick tube of it to turn like you would PR?
Have you tried wrapping your brass tube with a thinner layer of clay instead? Then bake it and if you aren't layering anything on top, you can lightly skew or wet sand it to your proportions.
I bake mine at 300 deg for about 30 min with a tinfoil "tent" over the top to keep the tops from turning color.
I've tried the ice water thing also and there wasn't any noticeable difference from my other ones.

 

[ghostrider]

I use Premo more than anything ... that and Kato.
If I am reading this right, you are trying to bake a thick tube of it to turn like you would PR?
Have you tried wrapping your brass tube with a thinner layer of clay instead? Then bake it and if you aren't layering anything on top, you can lightly skew or wet sand it to your proportions.
I bake mine at 300 deg for about 30 min with a tinfoil "tent" over the top to keep the tops from turning color.
I've tried the ice water thing also and there wasn't any noticeable difference from my other ones.

Thanks for the response.

I use Premo more than anything ... that and Kato.
If I am reading this right, you are trying to bake a thick tube of it to turn like you would PR?
Have you tried wrapping your brass tube with a thinner layer of clay instead? Then bake it and if you aren't layering anything on top, you can lightly skew or wet sand it to your proportions....

Both. The blowout my friend had with spongy clay was baked on the tube (That's mostly what I've been doing, but I have also made solid blanks also. The one that I just experimented with/burnt was a solid blank).

What I usually do after wrapping the tube (or forming the blank. whichever method I'm doing) is place them in a covered, Corningware (clear lid) dish filled with baking soda. Then cover the peices with ore baking soda (Tony Aquino from Kato suggested the baking soda) and the lid put on before baking.

Another method I sometimes use is to put them in some foil pans (with or without baking soda), and cover them with tin foil.

I realize I can't expect it to get as hard as the Kato baked at 325*, but I've tried just about everything I know of.

PS.
I was told that the ice water method made the clay more stable and less prone to blowout, but I also haven't noticed a difference.

 

[KnB Polymers]

Hmmm, I've never tried any of the ways you mentioned.
Try this and see what happens ...
wrap the tube with the clay (a little thicker than bushing size) ... I was gonna try explaining how I cook mine, but pictures say a thousand words. :biggrin: I put them on wood skewers and set them on top of the pan, then put the foil "tent". I put the pan in the center of the oven and bake. So far (knock on wood) I've never had mushy or soft tubes.
I'm no expert on any of this, just saying how I do mine.

 

[ghostrider]

Hmmm, I've never tried any of the ways you mentioned.
Try this and see what happens ...
wrap the tube with the clay (a little thicker than bushing size) ... I was gonna try explaining how I cook mine, but pictures say a thousand words. :biggrin: I put them on wood skewers and set them on top of the pan, then put the foil "tent". I put the pan in the center of the oven and bake. So far (knock on wood) I've never had mushy or soft tubes.
I'm no expert on any of this, just saying how I do mine.

I'll give that a shot. It's pretty much how I've done mine with the foil pans, but I didn't leave the tin foil tent open like that.

Thanks

 

[GoatRider]

What's the ice water method?

 

[ghostrider]

What's the ice water method?

Go straight from the oven to a dip in ice water. Supposed to also help the effect of translucent clay.